Silymarin Extraction From Silybum marianum L. Gaertner

Abstract Silymarin, a mixture of flavonolignans exhibiting many pharmacological activities, is obtained from the seeds of milk thistle ( Silybum marianum L. Gaertner). The common procedures used so far for silymarin extraction are based mainly on slow high-temperature solvent-extraction methods. The drawbacks associated with these techniques have led to the search for new alternative extraction processes that additionally could improve silymarin extracts quality. The latter is particularly important as regards silymarin application. The obtained silymarin extracts, in fact, could contain toxic organic residues that need to be removed to meet consumer acceptability. In the attempt to improve the process of silymarin extraction and make it more effective and environmentally friendly, recently microwave-assisted solvent extraction, ultrasound-assisted solvent extraction, pressurized liquid extraction, enzyme-assisted extraction, supercritical fluid extraction, and especially subcritical water extraction also known as pressurized hot water extraction methods have been developed and applied.